Here's my take on the Tamron with my 7d. I tested it out on flight shots of incoming lesser scaup, probably one of the most difficult shots for a camera and lens to keep up with, heck even the 100-400 isn't very good at this and the 400 prime is the best I've used for this but still misses it's share. The Tamron does track the birds in AIServo it's just not quite fast enough to keep up. The shots aren't totally oof there often just off by 6-12 inches or so. Initial focus is a little tough, often having to work the shutter a bit to get a lock. I never expected the Tamron to be better than the 400 at this, I was just hoping it would be close to the 100-400, which it is, not as good but close. Also can't test the 100-400 at 600mm either. I do experience the focus lock up when switching from a near object to far like everyone else so definitely an issue there. The other issue I noticed is when in one shot or AiServo and the focus limiter set to full, the focus will search every time when going from a bird say 15m away to one 20m away. The focus runs in then out every time, the 100-400 does this occasionally but nothing like the Tamron.

Below is a 4 shot burst at 600mm of an incoming bird. All very basic processing with the same amount of sharpening, some are sharper than others none are tack sharp but it shows the lens is at least trying to keep up..............

The Tamron cannot recognise contrast, it has no sensor. Older Canon cameras with the Tamron seem not to recognise contrast very well. Strangely my !00-400 on a 7D has a lot of the problems described in the previous post. It invariably hunts through the range and just looses me the shot. The strange thing is that it does this when I am 5 or 6 meters away from the target. The problems have to be in the cameras, with varying tolerances, ie no two cameras are totally equal, especially at the margins of usabilty in difficult light.

The Tamron cannot recognise contrast, it has no sensor. Older Canon cameras with the Tamron seem not to recognise contrast very well. Strangely my !00-400 on a 7D has a lot of the problems described in the previous post. It invariably hunts through the range and just looses me the shot. The strange thing is that it does this when I am 5 or 6 meters away from the target. The problems have to be in the cameras, with varying tolerances, ie no two cameras are totally equal, especially at the margins of usabilty in difficult light.

Mike Engles

The key is 'it hunts' my Tamron on my 1DMKIII would simply STOP focusing and not try, hunt or even chatter without releasing then again pushing the focus button. Same problem even on a stationary subject when switching to another target while in AI Servo.

Here is an interesting read about a Japanese product defect cover up (year 2000)

Mitsubishi Motors admitted today that it had systematically concealed customer complaints about tens of thousands of defective automobiles since 1977.

The admission by Mitsubishi, Japan's No. 4 automaker, came a month after its top executive had denied accusations that it had covered up problems that included faulty fuel tanks, clutches, crankshafts and brakes.

Under United States and Japanese law, automakers must notify the government about defects reported to them by customers. By ignoring this requirement, Mitsubishi had avoided potentially costly recalls, which are considered especially humiliating for a Japanese auto company.

''We sincerely apologize to the drivers of our cars,'' said Katsuhiko Kawasoe, president of Mitsubishi. ''My job is to work to regain the public's trust in this company.''

It was unclear how such a pattern of deception could have gone on for so long without the knowledge of high-level executives.

But Mr. Kawasoe, who said he had no knowledge of the cover-up until it was documented in an internal investigation submitted to the government today, promised that the company would punish those who were directly responsible. He also said he and other top Mitsubishi executives would take a salary cut to acknowledge their accountability. Mr. Kawasoe said, however, that he did not intend to resign.

The internal investigation found that Mitsubishi employees had repaired the defects but had initialed the customer complaints with an ''H'' for ''hitoku,'' which means conceal, or ''horyu,'' which means defer or hold. None of these complaints were reported to the government.

Karl Witt wrote:
The key is 'it hunts' my Tamron on my 1DMKIII would simply STOP focusing and not try, hunt or even chatter without releasing then again pushing the focus button. Same problem even on a stationary subject when switching to another target while in AI Servo.

Karl

Hello

I really do believe that those who believe the problem is in the Tamron lens are really in denial.
The camera controls the lens, if the camera is confused for any reason, the lens cannot do anything, but hang.
In standard focusiing, the camera will not fire unless there is focus confirmation, the focus led lights up.
This means that there is some sort of feedback loop between the camera and the lens.

In AI Servo, there is no confirmation of focus lock. The camera will fire away, whether focus has been achieved or not. So there are two possibilies, the camera AF sensor has difficulty in assessing contrast, so cannot control the lens properly, or the lens is too slow in reacting.The lens seems to react perfectly well in standard AF (focus confirmation), but will not follow focus in AI Servo, simply because AI Servo makes greater demands on the camera AF and it seems that older Canon cameras, cannot satsify those demands when controlling a Tamron 150-600.

As I have said before, my combination of 7D and Canon 100-400 regularly show exactly the same problems that beset the 7D and Tamron 150-600 combination. In marginal or backlit situations, my setup just hangs and needs constant stabs of the focus button, to coax it into focussing, thereby missing the shot.

The whole issue should be resolved, when a Nikon and/or Sony version of the lens is released.

Pat Simonetti
Director
Technical & Customer Service/Distribution
Tamron USA, INC
10 Austin Blvd
Commack, NY 11725
simonetti@tamron.com
Benn in contact with the above by email. I have lots of focus problems with this lens on my 50d. Pat says there are no problems... Let me quote him
"Let me start by saying there are no issues with older Canon camera bodies such as the 50D."
We all know that isn't true. When I told he I could not walk into a store and exchange it because they were back ordered. He said

"We cannot control what lenses and quantities our authorized dealers decide to stock. This is completely up to them."

This guy is in complete denial as to the focus and stock issues.plus from the looks of his job title he should be up to date on both.

I would send mine in for repair, but I think the problem lies more with the design of the lens. Not sure that can be fixed.

BTW I did invite him to join the board and answer questions... No comment from him.

The internal investigation found that Mitsubishi employees had repaired the defects but had initialed the customer complaints with an ''H'' for ''hitoku,'' which means conceal, or ''horyu,'' which means defer or hold. None of these complaints were reported to the government.

Kiwijoslin, you should ask him to speak to Tamron Europe, because I've been asked to send my lens in for a fix for the 'compatibility issues with the 7d & other bodies.' This came from the UK service centre yesterday, who told me that they'd been waiting until now for Japan to respond.I think I'll send mine in on Monday, the manager seemed to think it would be a fairly quick turnaround, so I'm hoping this will be good news for us all...

I really do believe that those who believe the problem is in the Tamron lens are really in denial.
The camera controls the lens, if the camera is confused for any reason, the lens cannot do anything, but hang.
In standard focusiing, the camera will not fire unless there is focus confirmation, the focus led lights up.
This means that there is some sort of feedback loop between the camera and the lens.

In AI Servo, there is no confirmation of focus lock. The camera will fire away, whether focus has been achieved or not. So there are two possibilies, the camera AF sensor has difficulty in assessing contrast, so cannot control the lens properly, or the lens is too slow in reacting.The lens seems to react perfectly well in standard AF (focus confirmation), but will not follow focus in AI Servo, simply because AI Servo makes greater demands on the camera AF and it seems that older Canon cameras, cannot satsify those demands when controlling a Tamron 150-600.

As I have said before, my combination of 7D and Canon 100-400 regularly show exactly the same problems that beset the 7D and Tamron 150-600 combination. In marginal or backlit situations, my setup just hangs and needs constant stabs of the focus button, to coax it into focussing, thereby missing the shot.

The whole issue should be resolved, when a Nikon and/or Sony version of the lens is released.

Mike Engles...Show more →
Mike the lens works on some bodies (newer ones) & not others. It isn't working at 300mm plus range in Servo mode the same way that my Sigma telephotos do, regardless of light conditions. It does on at 300mm and less. This, for me,confirms the lens is the problem & I am in no kind of denial! Quite simply, it doesn't do what similarly priced & spec'd (but older) lens do. A lens has been produced that I feel should work with every feature of my reasonably modern camera, unless otherwise stated. It's a long telephoto lens, therefore owners of this lens are more likely to be using Servo while using this lens as likely to be used for sports, wildlife etc. Exactly what Servo was designed for.
Hopefully all this will be irrelevant soon , as I've been asked to send mine inn for a fix!

I really do believe that those who believe the problem is in the Tamron lens are really in denial.
The camera controls the lens, if the camera is confused for any reason, the lens cannot do anything, but hang.
In standard focusiing, the camera will not fire unless there is focus confirmation, the focus led lights up.
This means that there is some sort of feedback loop between the camera and the lens.

In AI Servo, there is no confirmation of focus lock. The camera will fire away, whether focus has been achieved or not. So there are two possibilies, the camera AF sensor has difficulty in assessing contrast, so cannot control the lens properly, or the lens is too slow in reacting.The lens seems to react perfectly well in standard AF (focus confirmation), but will not follow focus in AI Servo, simply because AI Servo makes greater demands on the camera AF and it seems that older Canon cameras, cannot satsify those demands when controlling a Tamron 150-600.

As I have said before, my combination of 7D and Canon 100-400 regularly show exactly the same problems that beset the 7D and Tamron 150-600 combination. In marginal or backlit situations, my setup just hangs and needs constant stabs of the focus button, to coax it into focussing, thereby missing the shot.

The whole issue should be resolved, when a Nikon and/or Sony version of the lens is released.

The Tamron isn't only failing in marginal and back lit situations though is it? So not the same issue at all. Tamron sold a Canon compatible lens that clearly isn't, and it looks like they may have recognised that with a fix now? The camera functions can only perform based on the information it receives through the lens.

The lens has no AF sensing at all, so cannot control the camera, it can only transmit light to the camera AF sensor. Now it seems that is sufficient for Standard AF, but not on older cameras for AI Servo. From what I have read, the problem seems to be in light of low contrast.
There is no actual feedback loop from the lens, at least that is what a Canon engineer told me, when I complained about my Canon 100-400. It is possible that more recent lenses do have a lens position feedback loop. The Camera in standard focus measures the contrast by comparing light from two sides of the lens, and tell the lens to move to a particular focus position. At a point of maximum contrast, it assumes the lens is in the correct focus and allows the shutter to fire. This does not happen in AI Servo

Now if all cameras are affected, in all situations then that is a different matter, but a lot of people have posted fine pictures using more recent Canon cameras and have reported no problems. At the moment there is not enough data from owners of more recent Canon cameras, to know if it a more general problem.

The lens has no AF sensing at all, so cannot control the camera, it can only transmit light to the camera AF sensor. Now it seems that is sufficient for Standard AF, but not on older cameras for AI Servo. From what I have read, the problem seems to be in light of low contrast. Now if all cameras are affected, in all situations then that is a different matter, but a lot of people have posted fine pictures using more recent Canon cameras and have reported no problems. At the moment there is not enough data from owners of more recent Canon cameras, to know if it a more general problem.

You still don't grasp the concept of Tamron selling a Canon compatible lens that isn't. If they released the lens clearly defining the compatible bodies there wouldn't be an issue. The issue lays with Tamron, no one else. The 7D is still a current Canon camera.

This all sounds exactly like the problems with the 1d3 when it was initially released and Canon was in full denial of any problems...but did have their pink dot release that fixed this "non problem". I'm sure Tamron will do the same. Just give them some time.

surfinrobin wrote:
Kiwijoslin, you should ask him to speak to Tamron Europe, because I've been asked to send my lens in for a fix for the 'compatibility issues with the 7d & other bodies.' This came from the UK service centre yesterday, who told me that they'd been waiting until now for Japan to respond.I think I'll send mine in on Monday, the manager seemed to think it would be a fairly quick turnaround, so I'm hoping this will be good news for us all...

jj_glos wrote:
You still don't grasp the concept of Tamron selling a Canon compatible lens that isn't. If they released the lens clearly defining the compatible bodies there wouldn't be an issue. The issue lays with Tamron, no one else. The 7D is still a current Canon camera.

That is part of the problem. The other part is their denial.that is crazy.

mikeengles wrote:
From what I have read, the problem seems to be in light of low contrast.

Well maybe you should read the threads here again. It would not focus on a black and white subject in bright light. Can't get much more contrasty than that. Every other Canon, Sigma, and Tamron lens I have owned had no problem changing focus on any Canon body under less contrasty conditions. Guess it must be the fault of the body eh?

On the thread about how many people have returned the lens, one user had the same problem with a 5D3 and 1DX.

As pointed out several times, it is supposed to be a Canon-compatible lens, not a body-specific lens.

Perhaps if you owned the lens and experienced the problem, you might know what you are talking about.